30kW – 97% Efficiency Isolated DC-DC Converter with Large Input Voltage Range Based on a BOOST-DAB Association

This paper presents a 30kW - 97% efficiency isolated DC-DC converter with fixed (200V or 400V) regulated output voltage and wide range (200V to 600V) input voltage. After theoretical investigations on single stage isolated converters, our main orientation was to design a Dual Active Bridge (DAB) with fixed input and output voltages, to ensure galvanic insulation with very high efficiency. The fixed input voltage of the DAB is provided by an 8-phase interleaved BOOST converter. An original planar transformer structure has been designed for the DAB. Experimental results for the full structure are presented in the article.